1. Field of the Invention
The present invention relates to a connector including a receptacle and a plug which are engaged with each other to be electrically connected to each other.
2. Description of the Prior Art
In a conventional connector including a receptacle and a plug which are engaged with each other to be electrically connected to each other by inserting the plug into an insertion groove formed in the receptacle, a further reduction in height of the connector is now in increasing demand with the miniaturization of portable terminal equipment or other devices which adopt this type of connector. However, with this height reduction of the connector, the holding force for holding the engagement of the receptacle with the plug tends to decrease, which makes it easy for the receptacle and the plug to be undesirably disengaged from each other.
On this account, a type of connector with a lock mechanism, wherein contacts (terminals) of the receptacle are provided with lock lugs while a plug body (insulating housing) of the plug is provided with corresponding engaging projections engageable with the lock lugs, respectively, has been proposed. This type of connector is disclosed in Japanese Unexamined Patent Publication H09-259979. In this type of connector, the holding force for holding the engagement of the receptacle with the plug is improved by making the lock lugs and the engaging projections engaged with each other, respectively, upon the plug being inserted into the receptacle.
On the other hand, in conjunction with the achievement in height reduction of the connector, a type of connector in which a column projecting from a center of an insulator of the receptacle is provided symmetrically on opposite sides of the column with a pair of movement preventive portions, respectively, to prevent ends of the contacts of the receptacle from being curled up upon the plug being extracted from the receptacle. This type of connector has been proposed in Japanese Unexamined Patent Publication 2001-338711.
However, in the above described connector disclosed in JUPP 2001-338711, in which contacts of the receptacle are provided with lock lugs, the plug body of the plug, on which the engaging projections are formed, wear out over time as the plug is repeatedly inserted into and extracted from the receptacle, which causes the plug body of the plug to produce dust or shavings and further causes the engaging projections to be deformed to thereby lower the holding force for holding the engagement of the receptacle with the plug.
In JUPP 2001-338711, in which the receptacle is provided with the pair of movement preventive portions, the height of the pair of movement preventive portions needs to be reduced if it is desired to achieve a further reduction in height of the connector. However, since this reduction deteriorates the strength of the movement preventive portions, there is a possibility of ends of the contacts of the receptacle not being prevented from being curled up. Additionally, even if this curling can be prevented from occurring, there is a possibility of the contacts which are engaged with the pair of movement preventive portions not returning to their original positions; this type of connector in which the contacts of the receptacle no longer return to the original positions cannot make full use of the capabilities of the connector.